SSH-AGENT(1)SSH-AGENT(1)
NAME
ssh-agent - SSH authentication agent
SYNOPSIS
ssh-agent [ -l ] factotum-service
DESCRIPTION
Ssh-agent presents factotum(4) using the interface that
ssh(1) requires.
Once ssh-agent and factotum are running, the standard Unix
SSH client can use ssh-agent (and, indirectly, factotum) to
authenticate to remote systems using RSA or DSA keys.
Ssh accesses ssh-agent via a Unix socket named
ssh-agent.socket in the name space directory (see intro(4)).
Note that although the socket is posted in the name space
directory, it is not for 9P conversations. Ssh expects the
name of this socket to be in the environment as
$SSH_AGENT_SOCK, and expects the agent to be running with
process id $SSH_AGENT_PID. Ssh-agent prints shell commands
to set these two variables before forking itself into the
background. It is typically invoked inside a shell eval
construct; see the examples below. The -e option causes
ssh-agent to include export commands to put the variables
into the environment of future programs.
If the -l option is given, ssh-agent lists the usable
factotum keys in the standard SSH format, suitable for cre-
ating an authorized_keys file.
Ssh-agent connects to factotum by accessing factotum-service
(default `factotum') in the current name space.
There is a Unix program called ssh-agent that manages SSH
keys itself. Invoke this one with 9 ssh-agent; see 9(1).
EXAMPLES
Assume factotum(4) is already running and initialized with
keys.
Start a new agent, copying the commands by hand:
$ 9 ssh-agent -e
SSH_AUTH_SOCK=/tmp/ssh-405795003d7ee27a/agent.4233;
export SSH_AUTH_SOCK;
SSH_AGENT_PID=4233;
export SSH_AGENT_PID;
$ SSH_AUTH_SOCK=/tmp/ssh-405795003d7ee27a/agent.4233;
$ export SSH_AUTH_SOCK;
SSH-AGENT(1)SSH-AGENT(1)
$ SSH_AGENT_PID=4233;
$ export SSH_AGENT_PID;
$
Start the agent from sh(1):
$ eval `9 ssh-agent -e`
$
Start the agent from rc(1):
% eval `{9 ssh-agent}
%
Use the agent to connect to a remote system:
% ssh tux
tux% ^D
%
SOURCE
/src/cmd/auth/ssh-agent.c
SEE ALSO
ssh(1), rsa(1), factotum(4)
BUGS
A surprise rather than a bug: ssh-agent connects to factotum
on demand, so it can be started before factotum is running
and need not be restarted just because factotum is.